What is the exact number of unpaired electrons present in the ground state electronic configuration — Periodic Table and Periodicity Chemistry Question

💡 Solution & Explanation

The atomic number of Oxygen is 8. Its ground state electronic configuration is $1s^2 2s^2 2p^4$. According to Hund's rule of maximum multiplicity, the four electrons in the three degenerate 2p orbitals arrange as $\uparrow\downarrow$, $\uparrow$, $\uparrow$. Thus, there are exactly 2 unpaired electrons.